I would suggest that you start at www.pricegrabber.com - it provides a relatively easy way to sift through prices (include shipping costs calculated using your zip code). It also provides reviews and ratings from previous customers of vendors listed so it may be able to help you avoid problems with specific businesses prior to ordering from them.
That being said, based on my limited purchase experience from B&H (2 Canon SLR lenses) they seem to be a pretty safe bet and they have reasonable prices as well. On neither order did I receive any "confirmation" calls. The fact that the number I provided was a land-line which is listed in my name may have been a factor in that however.
